Yarn-tension device



A. M. PIGEON.

YARN TENSlON DEVICE.

APPLICATION FILED SEPT. 27. 1921.

1,435,495, Patented Nov. 14, 1922 INVENTOR. mam MI Pigeon,

ATTORNEY?- Patented Nov. 14, 1922.

UNITED STATES ALBERT M. PIG-EON, OF NORRISTOWN, PENNSYLVANIA.

YARN-TENSION DEVICE.

Application filed September 27, 1921. Serial 110. 503,485.

T 0 all whom it may 0011 061% Be it known that I, ALBERT M. PIGEON, a citizen of the United States, residing in Norristown, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Yarn-Tension Devices, whereof the following is a specification, reference being had to the accompanying drawings.

My invention relates to yarn tension devices useful generally in connection with textile machinery, but more especially with knitting machines in maintaining the yarn under constant tension in the course of feedlilany attempts have heretofore been made, especially in the case of knitting machines, to maintain at all times, uniform tenslon upon the yarn with a view toward preventing irregularities in the length of work produced. The devices employed to this end, while capable of overcoming this difliculty to a certain extent, were however not wholly efficient in attaining the real or desired objective. This inefficiency I have found to be due to their incapacity to compensate properly for variations or fluctuations in the drag or resistance of the yarn as it 1s drawn from supply bobbins. Such drag or resistance may var for many reasons, amongst which the following may, by Way of example, be mentioned: differences in the quality or character of the yarn; contributory effects of atmospheric conditlons or changes; differences in the method or style of winding the cops or bobbins; or 1rregularities in the tightness of the winding.

The paramount object of my invention is to overcome the difficulty above pointed out, and this I accomplish by controlling the degree of a tension separately induced in the yarn compensatively in accordance with the magnitude of the drag or resistance offered in unwinding from the supply cop or bobbin in such a manner that a constant resultant working tension is assured.

Other objects and advantages of my 1nvention will become apparent from the detailed description which follows:

In the drawings, Fig. I is an illustration of a yarn tension device conveniently embodying my invention.

Fig. II is an elevation of the structure viewed from the right of Fig. I; and

Fi III is a detail cross section along line II-III of Fig. II.

The several moving parts of the organiza? tion herein shown are supported by an L shaped bracket 1 which may be attached in any convenient manner to the machine whereto the yarn is to be fed. In the present instance I have illustrated the bracket 1 as being suspended from the end of a horizontal extremity 2 of a yarn guide tree (not shown) such as ordinarily employed, for example, in connection with stocking knitters, and secured by means of screw 3 which passes through an appropriate opening in the end of arm 2 to engage with the lateral turned top portion 4 of the bracket. The vertical portion 5 of the bracket has, at a point somewhat above the horizontal arm 6, an integral outstanding boss 7 which is axially bored for anchorage of a. fixed stem 8. On this stem are mounted, with capacity for free rotation, a pair of opposed tension discs 9 and 10 which, as best seen in Fig. II, are dished in cross section and yieldingly maintained in pressure contact with each other and the end of the boss 7 by means of a helical spring 11 which encircles the stem 8. Coordinated with the tension discs 9 and 10 is a yarn guide eye 12, which is secured in the horizontal arm 6 of the bracket 1 below the said discs and a spool shaped reguide element 13 located above said discs and secured to the vertical portion 5 of the bracket, preferably near the top of the latter. From Fig. I it will be apparent that the tension discs 9, 10, the guide eye 12, and the reguide element 13 are disposed in vertical alignment, and also more especially from Fig. II

that the surface of the member 13 is concaved with the center of curvature lying in the plane of abutment of the discs 9 and 10, so that the yarn indicated at Y in the course of being reversed in the direction of its travel, as will be hereinafter more fully explained, is automatically maintained properly centered with respect to the disks.

In order that the pressure between the discs may be compensatively varied in accordance with the drag or resistance induced in the yarn as it is unwound from the supply cop or bobbin so that a constant resultant working tension may be secured under all conditions of feeding, I have provided for co-operation with said discs, automatically operative regulating means, which I will now proceed to describe. In the present instance, this regulating means includes an arm 15 which is fixed to a shaft 16 mounted the yarn eye 21 is counterbalance for rotation in an immovable sleeve 17 secured in an up-standing lug 18 of the bracket 1. From the outer endof the arm 15 extends laterally, a stem 19 whose free extremity is bent into the form ofa loop 20, for retainment of a yarn eye 21. The movement of the arm 15 is limited by an element 22 having stop projections 23 and 24 which lie in the path of movement of the boss 26 of said arm. This stop element is, secured with capacity for adjustment to the stationary sleeve 17, a set screw 27 being employed to fix the same in any desired adjusted position.

The movements of the arm 15 are communicated to the spring 11 through the instrumentality of the upturned flattened end 30 of the shaft 16 which plays within a slot 31 at the outer extremity of the mounting stem 8 and engages with the corresponding end of said spring. Operative in opposition to the pull on the yarn Y. as it passes through the movable yarn eye 21, is a counterweight 32. Said counterweight, it will be noted, is secured upon a rod 33, extending in an angular direction from the hub of the arm '15. By reason of the angular positlon of the counterweight 32 relative to the arm 15 and its disposal at a point above the level of the fulcrum shaft l6,'its leverage, and consequently its efi'ectiveness, increases gradually as the arm is moved clock-wise and vice versa when the same is moved in a counter direction. Thus it will be apparent that the counterweight serves to augment the action of the sprm 11 gradually as additional tension is nee ed, and in this way precludes the possibility, at any time, of the spring becoming retroactive upon the same. Adjustment of the counterweight may be had by shifting the same along the rod 33 as a consequence of which the ull on to a greater or lesser extent. By this provision,

the regulating means may be set to maintain any desired resultant working tension in the yarn in satisfyingthe various demands of practice.- In order to prevent spasmodic operation of the regulating means, I have provided a retarding device in the form of a dash pot comprehensively indicated at 35. The cylinder 36 of the dash pot is pivotally suspended from the stem 19 which su ports the movable guide eye 21. Cooperative with the cylinders 36, is a piston 37, the latter being mounted, with capacity for a certain extent of universal motion, to a depending extension 38 of the bracket 1. For this purpose I employ, preferably, a headed stud such as shown at 39 whose shank plays freely in an opening 40 in the end of the extension 38 and is screwed axially into the piston 37.

In operation, the yarn Y as it is drawn masses is guided by the stationary eye 12 to pa: tangentially between the tension discs 9'an 10 at one side of the mounting stem 8. Afte emerging from between the discs, the yarn continues in its upward travel and passes about the member 13 whereby it is 'reguided to move downwardly and reeves tangentially between the tension discs 9 and 10 at the opposite side of the stem 8. Following the course of the yarn still further, it will be observed to pass again through the stationary eye 12 and is thereafter diverted from a vertical path to pass horizontally through the movable eye 21 carried by the arm 15 of the regulating means from whence it is directly led to the needles of the knitting machine. By reason of the several abrupt changes in the direction of travel of the yarn and the uniform pressure exerted by the discs by the spring 11 under normal functioning of the regulator mechanism, the yarn will be maintained at constant even tension in the course of being fed to the consuming machine. If, for any reason, the drag or resistance induced in the yarn in unwinding from the cop orbobbin should become heavier, the added pull will, through the instrumentality of the movable eye 21,

cause the regulator arm 15 to be shifted, 1

lieve the spring 11 in accordance with the magnitude of the added pull. Such action will obviously cause diminution of the pressure between the discs 9 and 10 so that the resultant working tension of the yarn as it is fed to the knitting machine will be the same as under normal operation. Again, let it be assumed that the drag of the yarn in unwinding from the supplycop or bobbin. should for any reason become lighter, such relaxation will allow the regulator arm 15 to shift in a clock-wise direction under the action of its counter weight 32, with the result that power of the spring 11 is augmented, and the pressure between the tension discs correspondingly increased. By this compensative action, the predetermined constant resultant working tension will be maintained in the yarn as before. In the course of its operation the regulator arm 15 is rendered proof against spasmodic impulses through the stabilizing action of the dash pot 35, and undue oscillation of said arm is prevented by the stop lugs 23 and 24 of the element 22. The proportioning of the various constituent parts of the structure is such that all needed regulation of tension of the spring 11 may be controlled within the limits of oscillation of the arm 15 imposed by the stops 22 and 23. In normal operation the boss at the end of the arm 15 floats at a point approximately mid-way between said stops.

from the supply cop or bobbin (not shown) By controlling the tension of the yarn in accordance with my invention, I am enabled to produce work which is absolutely uniform as to stitch length regardless of the character of the knitting produced thus not only obviating losses due to irregularities such as hereinbefore pointed out, in the work, but, in addition effecting considerable saving in the yarn.

. Having thus described my invention, I claim:

1. A yarn tension device comprising a pair of opposed tension disks between which yarn is passed enroute from the supply cop or bobbin to the machine which is fed; resilient means for maintaining yielding pressure between said discs; in combination with regulating means coordinated with the aforesaid resilient means for varying the pressure between said discs compensatively in accordance with variations or fluctuations in the resistance or drag offered in unwinding the yarn from the supply cop or bobbin, to insure a constant, resultant working tension during feeding of the yarn; and a dash pot associated with the regulating means for preventing spasmodic operation of the latter.

2. A yarn tension device comprising a pair of opposed tension discs between which yarn is passed enroute from a supply cop or bobbin to the machine which is fed; resilient means for maintaining yielding pressure between said discs; in combination with regulating means coordinated with the aforesaid resilient means in varying the pressure between said discs compensatively in accordance with the fluctuations in the resistance or drag offered in unwinding from the supply cop or bobbin, said means including a freely fulcrumed arm; an attached eye through which the yarn is passed to actuate the arm; means whereby the movements of said arm are communicated to the aforesaid resilient means for the purpose of compensatively increasing or decreasing the pressure between the tension discs 'to insure a constant resultant working tension during feeding of the yarn; a dash pot associate with the regulating means for preventing spasmodic operation of the latter, including a cylinder pivotally attached to the arm; and a piston adapted for cooperation within the cylinder, said piston being attached to a fixed anchorage with capacity for universal movement in adjusting itself to various an gular movements of the cylinder.

3. A yarn tension device comprising a pair of opposed tension discs between which yarn is passed enroute from a supply cop or bobbin to the machine which is fed; resilient means for maintaining yielding pressure between said discs; in combination with regulating means coordinated with the aforesaid resilient means in varying the pressure between said discs compensatively in accordance with the fluctuations in the resistance or drag offered in unwinding from the supply cop or bobbin, said means including :1

reely fulcrumed arm; an attached eye through which the yarn is passed to actuate the arm; a counterweight operative in opposition to the pull upon said eye, said counterweight being set with capacity for adjustment upon a rod extending in an angular direction from the hub of the aforesaid arm; and a shaft to which the arm is fixed, said shaft having one end turned laterally to cooperate with the aforesaid resilient means for the purpose of compensatively increasing or decreasing the pressure between the tension disks to insure a constant working tension during the feeding of the yarn.

4. A yarn tension device comprising a pair of opposed tension discs between which yarn is passed enroute from a supply cop or bobbin to the machine which is fed; resilient means for maintaining yielding pressure between said discs; in combination with regulating means coordinated with the aforesaid resilient means in varying the pressure between said discs compensatively in accordance with the fluctuations in the resistance or drag offered in unwinding from the supply cop or bobbin, said means including a counterweighted arm; an attached eye through which the yarn is passed to actuate the arm; a shaft whereto the arm is fixed; said shaft having one end turned laterally for cooperation with the aforesaid resilient means for the purpose of compensatively increasing or decreasing the pressure between the tension disks to insure a constant resultant working tension during feeding of the yarn; a fixed sleeve wherein said shaft is journalled for free oscillation; and means for limiting the extent of free oscillation of the'shaft in the form of an element capable of being rotatively ad'usted about the journal sleeve and provi ed with spaced stop projections adapted to engage with the aforesaid arm.

5. A yarn tension device comprising a pair and between the discs at one side is reguided to pass in a like manner between the discs at the opposite side and then again through said stationary guide eye; aspring for maintaining yielding pressure between said tension discs; in combination with regulator means adapted to respond to variations or fluctuations in the resistance or drag induced in the yarn in unwinding from a supply cop or bobbin, including a freely fulcrunied counterweighted arm; an attached eye through which the yarn is passed subsequent to passage between the tension disks; and means whereby the movements of said arm are communicated to the aforesaid spring for the purpose of compensatively increasing or decreasing the pressure between the tension discs to insure a constant resultant working tension during the feeding of the yarn.

6. A yarn tension device comprising an L shaped supporting bracket; a pair of opposed discs mounted for free rotation upon a stem projecting horizontally from the vertical arm of said bracket; a stationary guide eye secured to the horizontal arm of the bracket below said discs in the plane of abutment of the latter; a reguide element secured to the vertical arm of said bracket at a point above said tension discs whereby the yarn, after having been guided through the stationary eye and between the discs at one sideis reguided to pass in a like manner between the disks at the opposite side and then through said stationary guide eye; a spring for maintaining yielding pressure between said tension discs; in combination with regulator means adapted to respond to variation or fluctuations in the resistance or drag induced in the yarn in unwinding from a supply cop or bobbin, including an arm; an attached eye through which the yarn is passed subsequent to passage between the tension disks; a shaft to which said arm is secured journalled for free oscillation in a lug of the horizontal arm of the aforesaid supporting bracket, said shaft having one end turned laterally for cooperation with the aforesaid spring; a counterweight operative in opposition to the pull on the eye on the aforesaidarm; and means for preventing spasmodic operation of the arm in the form of a dash pot comprising a cylinder pivotally connected to said arm; and a plunger piston secured to the end of the horizontal extremity of the supporting bracket with capacity for universal motion in adjusting itself to various angular move ments of the cylinder.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this 15th day of September, 1921.

ALBERT M. PIGEON.

Witnesses:

JAMES H. BELL, E. L. FULLERTON. 

